This study examined relationships between cancer patients' preferences for involvement in making treatment decisions and preferences for information about diagnosis, treatment, side effects, and prognosis. Participants were 35 women with stage I and II breast cancer recruited from two medical oncology and radiation oncology clinics. Following administration of card sort measures of preference for involvement in treatment decision making and information needs, a semi-structured interview was conducted to provide patients with an opportunity to elaborate on their role preferences and health care experiences. Results showed that patients who desired an active role in treatment decision making also desired detailed information. This relationship was not as clear for passive patients. Relative to passive patients, active patients desired significantly more detailed explanations of their diagnosis, treatment alternatives, and treatment procedures. Active patients also preferred that their physicians use the words 'cancer' or 'malignancy' when referring to their illness while passive patients preferred that their physicians use a eupheumism. Further research is needed to critically detail the advantages and disadvantages of the active and passive roles and their impact on disease progression and psychological well-being.